At the time of the 2000 Census, Jefferson Parish had an African-American population of 23%. In 1990 that rate was 18%. These numbers render it all the more striking that in the preceding two decades, Jefferson Parish has had 18 murder trials that ended with a conviction and death sentence, and of the 216 jurors who heard these cases, only 9 were Black. Seven of the 18 juries had but a single Black juror. Ten juries had no Black jurors at all. (Quick note of full disclosure: there were 2 additional trials ending with a death sentence during this time, but the racial demographics of those juries were not available to the researchers analyzing the data.)

If you do the math, this means that 4% of the jurors on capital murder trials in Jefferson Parish over the past two decades have been Black, a rate far lower than the 18-23% of African-Americans found in the population at large. In fact, the population rate suggests that a racially representative jury in Jefferson Parish would have 2 or 3 Black jurors, but during this time period, only 1 of the capital murder juries had as many as 2 Black members.

What explains the statistical aberration that is the racial makeup of Jefferson Parish capital juries? There are a number of factors that can contribute to nonrepresentative juries anywhere. In the U.S. (as well as other countries that use jury trials, including Canada, Australia, and New Zealand), racial minorities tend to be underrepresented on voter rolls, driver’s license lists, and other public records often used to compile source lists for jury duty. In addition, once jury duty summonses are sent out, non-Whites are less likely to report as requested than are White Americans. Some have speculated that this disparity reflects institutional mistrust of the legal system among many Black Americans, but it unquestionably reflects the fact that a disproportionately high rate of summonses sent to Blacks are returned by the post office to the courthouse as undeliverable.

However, those who have catalogued and analyzed the Jefferson Parish cases point to a different explanation for what has happened there, namely that local prosecutors have systematically gone out of their way to exclude Black citizens from serving as jurors in these trials. How would prosecutors do this? In large part by making use of a jury selection practice known as the peremptory challenge.

* * *

. . . [I]n 1986, the U.S. Supreme Court ruled that it was unconstitutional for attorneys to base their peremptory challenges on a prospective juror’s race (Batson v. Kentucky). Several years later, the prohibition was extended to prohibit gender-based peremptories as well. In both cases, the basis for the ruling was that such peremptory challenges violated the rights of all citizens, regardless of race or gender, to serve as jurors.

So what’s going on in Jefferson Parish, Louisiana? The 18 murder trials I described above all happened after the Supreme Court’s ruling in Batson. If the Court ruled that attorneys cannot base peremptories on juror race, why is it that only 4% of jurors on these capital murder trials have been Black? Well, it turns out that it’s just too easy for attorneys to get around the Batson ruling. As long as they’re able to provide the judge with a reasonable race-neutral explanation for their peremptory use, they won’t be found in violation of the rules. And if there’s one thing we know from psychological research on judgment and decision-making, it’s that people are remarkably good at coming up with plausibly neutral explanations for potentially biased choices.

Indeed, I and a colleague, Mike Norton of Harvard, conducted an experiment that illustrated this process in a jury selection setting. We asked college students, law students, and trial attorneys to make judgments in a jury selection simulation involving the trial of a Black defendant. We presented them with two prospective jurors, A and B, and asked participants to assume the role of prosecutor in the case. When photos revealed that Juror A was Black and Juror B was White, participants were more likely to use a peremptory challenge to remove A. But when we kept the information about Jurors A and B the same and simply switched their photos, suddenly B, now the Black juror, was more likely to be challenged. In other words, regardless of the personal and ideological information provided for each prospective juror, participants were basing their challenge decisions on race. And when we asked participants to justify their peremptories? They never talked about race, instead inflating the importance of race-neutral information that supported their challenge, in true top-down fashion.